Why do I need to Dispose a System.Net.Mail.MailMessage instance?

Question

What unmanaged resources does it allocates that needs to be disposed? Isn\'t it just a simple array of managed data? So why disposing?

Answer 1

A MailMessage can have attachments, an attachment is represented by MIME part which itself holds a Stream. This Stream needs closing as it might hold an unmanaged pointer to the underlying data.